Echocardiographic evaluation of intracardiac venous gas emboli following in-water recompression.

Decompression sickness is a potentially fatal illness. Optimal treatment is dry recompression with hyperbaric oxygen. In-water recompression (IWR) offers expedited treatment but has insufficient evidence to recommend it as a treatment option. This trial compares IWR to standard surface oxygen treatment using 2D echocardiography as the semi-quantitative measurement for inert gas loading. Divers were randomly assigned to either IWR or normobaric oxygen (NBO2). A provocative dive profile to 33.5 meters for 25 minutes was used to stimulate bubble formation. After 60 minutes on the surface, bubble scoring was obtained using 2D echocardiography. Divers underwent either the IWR or NBO2 treatment for 82 minutes. Echocardiography was then repeated. Pre-treatment mean bubble counts were 28.1 bpf (bubbles per echo frame), [+/- 13.2 to 43.0 95% CI] for IWR, and 18.3 bpf [+/- 0.0 to 39.6 95% CI] for NBO2. After treatment, mean bubble score dropped to 0.1 bpf [+/- 0.0 to 0.2 95% CI] (p < 0.01) and 1.8 bpf [0.0 to 3.8 95% CI] (p = 0.103) respectively. IWR vs. NBO2 reduction of bubble counts was 99.7% vs. 90.1%; however, this was not found to be statistically significant. IWR reduced the central VGE load compared to NBO2, suggesting that IWR is a viable emergency treatment when a recompression chamber is unavailable.

Bubble CPAP: is the noise important? An in vitro study.

Continuous positive airway pressure (CPAP) is often used to provide noninvasive respiratory support in infants with Respiratory distress syndrome. The recruitment of atelectatic lung and appropriate lung volume maintenance are vital to the success of CPAP treatment. The noisy pressure waveform of bubble CPAP superimposed on pressure fluctuations as a result of spontaneous breathing may promote airway opening events as a result of stochastic resonance. The magnitude and the frequency of the superimposed noise are critical to this process. We hypothesized that the applied bias flow and mechanical properties of the lung would influence the magnitude and the frequency content of the noise transmitted to the lung. The effect of varying bias flow (6-10 L/min) and lung compliance (0.1-1.5 mL/cm H(2)O) on the mean, range, and frequency content of the pressure fluctuations at the airway opening and within the lung was evaluated in an in vitro model lung. Increasing bias flow increased the mean and the magnitude of pressure oscillations at the airway opening and in the lung model. Decreasing compliance of the lung model increased the magnitude and the frequency content of pressure oscillations in the model lung. Lung mechanics and applied flow influence the magnitude of the noise superimposed on the transmitted pressure waveform and may influence lung volume recruitment in bubble CPAP.

Inadvertent stenting of left main coronary artery complicated by later in-stent restenosis.

Stenting of both the protected and unprotected left main coronary artery has been described. This case presents a patient who had inadvertent left main stent deployment. A 47-year-old female presented with a non-Q-wave infarction and subsequent angina leading to angiography and angioplasty of her proximal ramus intermedius artery. Recurrent angina and ECG changes necessitated repeat coronary angiography and angioplasty on the same day with Wiktor stent deployment to treat a resultant dissection. Poststent deployment pictures revealed that the stent had been partially deployed in the left main coronary artery. Additional balloon dilatations were performed at the ostia of the left anterior descending and circumflex arteries through the stent. Three months later the patient presented with progressive angina and was discovered to have severe distal left main stenosis. In a case such as this, stent removal may be preferable to leaving an unnecessary stent within the left main coronary artery. Cathet. Cardiovasc. Intervent. 48:194-197, 1999.

Emergency left main stenting in the management of postcoronary bypass graft surgery (CABG) ischemia.

Angioplasty has been used in the management of postcoronary bypass graft myocardial ischemia/infarction. A stent was successfully deployed in the left main artery in a patient with postcoronary bypass graft ischemia with hemodynamic instability. This case illustrates the potential use of emergency left main stenting in a selected patient with peri-operative ischemia, who was considered high risk for re-operation.

Catheter-induced acute aortic insufficiency with hemodynamic collapse during PTCA: an unreported complication.

Primary PTCA as a means of reestablishing coronary blood flow in the infarct related artery is preferable in certain subgroups of patients with acute myocardial infarction. While the success rate of primary PTCA is very high, the procedure is not without risk. We report a case of hemodynamic collapse during PTCA due to an Amplatz guide catheter-induced, acute, and reversible aortic insufficiency. With the increasing use of the left Amplatz catheter for better guide support during PTCA, this unusual and previously unreported complication should be borne in mind.

Anterior interosseous nerve syndrome due to aneurysm of arterio-venous fistula.

Weakness of the thumb, index, middle fingers developed over several days in a 48-year-old man with end-stage renal disease and an arteriovenous fistula in that arm. A large thrombosed aneurism was found and was shown to be compressing the anterior interosseous nerve (a branch of the median nerve). Surgical resection was followed by marked neurologic improvement. This syndrome is compared with two other median nerve compression syndromes (the pronator and carpal tunnel syndromes).

Refractory anaphylactoid shock potentiated by beta-blockers.

Allergic reactions, including anaphylactoid shock due to contrast material, are not uncommon. However, persistent anaphylactoid shock refractory to conventional therapy is rare. We present a case of refractory anaphylactoid shock during coronary angiography unresponsive to aggressive standard therapy in a patient on beta-blockers. Significant clinical improvement was noted upon administration of glucagon. Since beta-blockers are commonly used in patients with coronary artery disease, this potentially life-threatening complication has to be kept in mind with any procedure involving contrast media in patients on beta-blockers. Immediate access to glucagon by keeping it in the procedure room may be lifesaving in these situations.